Gemstones have their own unique optical response and this optical response can be used for accurate identification of the gemstones. In this regard, U.S. Pat. No. 3,947,120 discloses an arrangement for providing an optical fingerprint of a gemstone where a laser beam is focused on a gemstone and the optical response of the gemstone is recorded on a recording medium, preferably a photographic medium. This arrangement provides a fingerprint of the gemstone which is reproducible and has been held by the courts to be sufficient evidence to prove that the gemstone under consideration having a certain optical response is the same as a previously identified gemstone having essentially the same optical response.
The traditional techniques for evaluating how well a gemstone is cut are very subjective in nature and therefore, subject to different interpretation and also suffer from a lack of complete reproducibility. For example, to properly judge the cut of a diamond, one must know the table diameter (%), the crown angle (in degrees), the pavilion depth (%), the girdle thickness (%), and the culet size, as well as the angles by which they are joined. This sort of information is commonly found for diamonds which have a certification (commonly from GIA, AGS, GCAL, or EGL). Depending upon the cut of the diamond (e.g., round brilliant cut), various laboratories provide different proportions for their top level of cut, which can be “ideal” or “excellent” cut.
As will be appreciated, this type of traditional evaluation of the quality of the gemstone cut is based entirely on the dimensions of the cut and fails to take into account the quality and internal structure of the stone itself. In other words, the ranking of diamond cuts by evaluating the dimensions of the cut assumes a flawless diamond and therefore, most diamonds are not flawless, this traditional system does not take into account the quality and internal structure of the diamond.